1. Field of the Invention
The present invention relates to an apparatus for supplying and press-fitting a part to a work.
2. Description of the Related Art
FIG. 8 is an appearance perspective view around a smaller end of a connecting rod W, which is a component of an engine of such a vehicle, and a bush P press-fitted into the smaller end. FIG. 9 shows a section of a main portion of the bush P. On an inner peripheral face of the bush P is formed an oil groove Pa. In press-fitting such the bush P into a press-fit hole Wa of the connecting rod W, it is requested to strictly positioning a position and direction of the oil groove Pa and thereafter to press-fit the bush P into the hole Wa. In another process after the press-fit, an oil hole is integrally drilled that fronts the oil groove Pa of the bush P from an outside face of the smaller end of the connecting rod W.
A conventional method of supplying and press-fitting the bush P into the connecting rod W consists of: firstly detecting a cutout Pc of a detected portion provided at an edge of the bush P and positioning the bush P; next gripping and supplying the bush P to a press-fit head apparatus by robot arm functioning as a transfer apparatus; and press-fitting the bush P into the connecting rod W. Meanwhile, another conventional example relating to a press-fit apparatus is described in Japanese Patent Laid-Open Publication No. H 04-275836 (paragraph 0011, FIG. 1).
In the conventional method of supplying and press-fitting the bush P, because the bush P slightly oscillates in some case in a grip operation and release operation of a grip claw of a robot arm, the bush P may be displaced and press-fitted due to the oscillation after being positioned, in spite of having taken the trouble to position the bush P, in a configuration of making the robot arm intervene. Meanwhile, in the Japanese Patent Laid-Open Publication No. H 04-275836, if although there is no description relating to a positioning device because of a part needless of positioning, there is a need for the positioning, it is assumed that there will occur the similar problem in a case that the positioning device is provided at a more upstream side than an X-Y robot handling apparatus described in the paragraph [0011] of the H 04-275836. In addition, in the conventional method of supplying and press-fitting the bush P, because an optical sensor such as a laser sensor is used as a sensor for detecting the cutout Pc, there also exists a problem that a whole system is apt to become expensive.
Consequently, when positioning an annular part in a circumferential direction and thereafter supplying and press-fitting the part to a work, there is a need for an apparatus for supplying and press-fitting the part (hereinafter referred to as part supplying and press-fitting apparatus as needed) that reduces a positional displacement in a supply process and is also economical.